Use of Helicopter Emergency Medical Services in the Transport of Patients With Known or Suspected Coronavirus Disease 2019.

OBJECTIVE: Limited information exists regarding the response of helicopter emergency medical services (HEMS) programs to patients with known or suspected coronavirus disease 2019 (COVID-19). The purpose of this study was to determine changes in flight operations during the early stages of the pandemic. METHODS: A survey of the American College of Emergency Physicians Air Medical Section was conducted between May 13, 2020, and August 1, 2020. COVID-19 prevalence was defined as high versus low based on cases > 2,500 or ≤ 2,500. RESULTS: Of the 48 respondents, the majority (89.6%) reported that their patient guidelines had changed because of COVID-19; 89.6% of programs reported transporting COVID-19-positive patients, whereas 91.5% reported transporting persons under investigation. The majority of respondents reported additional training in COVID-19 airway management (79.2%) and personal protective equipment use (93.6%). Permitted aerosol-generating procedures included bilevel positive airway pressure (40.4%) and high-flow nasal oxygen (66.0%). No difference in guideline changes, positive COVID-19/persons under investigation transport restrictions, or permitted aerosol-generating procedures were noted between high- and low-prevalence settings. CONCLUSION: COVID-19 has resulted in changes to HEMS guidelines regardless of local disease prevalence. The pandemic has persisted sufficiently long that data regarding the effectiveness of guideline changes should be analyzed. In the absence of definitive data, national best practices should be developed to guide COVID-19 HEMS transport.

Precise Limb Tourniquet Arterial Occlusion Pressure Determination using Real-Time Ultrasonography and a Capacitive-Based Force Sensor.

BACKGROUND: Hemorrhage control prior to shock onset is increasingly recognized as a time-critical intervention. Although tourniquets (TQs) have been demonstrated to save lives, less is known about the physiologic parameters underlying successful TQ application beyond palpation of distal pulses. The current study directly visualized distal arterial occlusion via ultrasonography and measured associated pressure and contact force. METHODS: Fifteen tactical officers participated as live models for the study. Arterial occlusion was performed using a standard adult blood pressure (BP) cuff and a Combat Application Tourniquet Generation 7 (CAT7) TQ, applied sequentially to the left mid-bicep. Arterial flow cessation was determined by radial artery palpation and brachial artery pulsed wave doppler ultrasound (US) evaluation. Steady state maximal generated force was measured using a thin-film force sensor. RESULTS: The mean (95% CI) systolic blood pressure (SBP) required to occlude palpable distal pulse was 112.9mmHg (109-117); contact force was 23.8N [Newton] (22.0-25.6). Arterial flow was visible via US in 100% of subjects despite lack of palpable pulse. The mean (95% CI) SBP and contact force to eliminate US flow were 132mmHg (127-137) and 27.7N (25.1-30.3). The mean (95% CI) number of windlass turns to eliminate a palpable pulse was 1.3 (1.0-1.6) while 1.6 (1.2-1.9) turns were required to eliminate US flow. CONCLUSIONS: Loss of distal radial pulse does not indicate lack of arterial flow distal to upper extremity TQ. On average, an additional one-quarter windlass turn was required to eliminate distal flow. Blood pressure and force measurements derived in this study may provide data to guide future TQ designs and inexpensive, physiologically accurate TQ training models.

The Efficacy of Novel Commercial Tourniquet Designs for Extremity Hemorrhage Control: Implications for Spontaneous Responder Every Day Carry.

INTRODUCTION: Tourniquets (TQs) save lives. Although military-approved TQs appear more effective than improvised TQs in controlling exsanguinating extremity hemorrhage, their bulk may preclude every day carry (EDC) by civilian lay-providers, limiting availability during emergencies. STUDY OBJECTIVE: The purpose of the current study was to compare the efficacy of three novel commercial TQ designs to a military-approved TQ. METHODS: Nine Emergency Medicine residents evaluated four different TQ designs: Gen 7 Combat Application Tourniquet (CAT7; control), Stretch Wrap and Tuck Tourniquet (SWAT-T), Gen 2 Rapid Application Tourniquet System (RATS), and Tourni-Key (TK). Popliteal artery flow cessation was determined using a ZONARE ZS3 ultrasound. Steady state maximal generated force was measured for 30 seconds with a thin-film force sensor. RESULTS: Success rates for distal arterial flow cessation were 89% CAT7; 67% SWAT-T; 89% RATS; and 78% TK (H 0.89; P = .83). Mean (SD) application times were 10.4 (SD = 1.7) seconds CAT7; 23.1 (SD = 9.0) seconds SWAT-T; 11.1 (SD = 3.8) seconds RATS; and 20.0 (SD = 7.1) seconds TK (F 9.71; P <.001). Steady state maximal forces were 29.9 (SD = 1.2) N CAT7; 23.4 (SD = 0.8) N SWAT-T; 33.0 (SD = 1.3) N RATS; and 41.9 (SD = 1.3) N TK. CONCLUSION: All novel TQ systems were non-inferior to the military-approved CAT7. Mean application times were less than 30 seconds for all four designs. The size of these novel TQs may make them more conducive to lay-provider EDC, thereby increasing community resiliency and improving the response to high-threat events.